I once spent a month walking Simba the puma at the Inti Wara Yassi wildlife refuge in Bolivia. Every morning I greeted him in his cage hidden deep in the bush and we spent the next eight hours exploring the jungle. Recently I learned that Simba has passed away. Puma-walking was one of my favorite experiences in South America. Though our lives only intersected briefly I often think about Simba and his tragic-yet-heartening life story. RIP Simba. I miss you amigo.